Remediating tables already tagged across pages.NOTE: the Table Editor must be involved from the g&h tables checkpoint in Section 508 or OK Standards modes to sucessfully remediate tables that cross pages.

Restructuring tables to make the information more accessible using assistive technology.

Linked Headers

Table headers don’t always come in nice simple rectangular grids. In complex tables, headers may be stacked; they may occur far up the page, away from the grid of <TD> cells. They may even be scattered about the page. In these cases (see the example below), you can use CommonLook PDF to link cells to their headers to provide accessible navigation of complex tables to assistive technology users.

Before linking cells to headers you need to first ensure that all header cells are defined as such (TH) and set the scope if appropriate. In the example shown above the “Grand Total” cell is a <TH> with a scope of Row.

Assigning (Linking) a Header

To link the Grand Total <TH> to it’s header (the “City” <TH>), follow the four steps indicated in the screen-shot above:

Select the cell to be linked to a header.

Click the Modify button under the Linked Headers window.

Select the header cell and click “Add”

Click “Assign” to link the Grand Total <TH> to the City <TH>.

When the Linked Headers dialog closes you’ll see the selected cell’s header listed in the Linked Headers window.

Appending a Header

While the Assign button in the Linked Headers dialog overwrite’s the cell’s current header assignment, appending simply adds the 2nd header assignment below the first.

Demonstration

The following video demonstrates the use of CommonLook PDF to add linked headers to table data cells.

Table Properties Tab

The table properties tab provides options for the assitive technology user’s experience of the table and for accessibility verification procedures.

Verification Options

In general, if table tags have been used to tag non-tabular information, table tags should not be used and should be replaced in the tags tree with list, heading and paragraph tags as appropriate.

From a remediation workflow point of view, however, it may occasionally be necessary to specify the table as presentation or data. If using the linearize table function is not an option and it is a presentation table, this must be indicated here, otherwise the table will not validate.

The Presentation Table option should be used only in cases of tables that legitimately do not include header rows or columns. An example of such a presentation table is a Sudoku board.

The Validate button causes CommonLook PDF to review the table’s current structure for internal errors. It does not serve to verify that the table tags correctly represent the table’s actual structure.

Generate / Clear Speak Text

Not all software that voices PDF files can read table tags. To accomodate specific users or reading applications, CommonLook PDF’s Table Editor allows for the creation of SpeakText. This feature copies each cell’s headers into the cell’s content such that even linear readers that know nothing of tags can get a sense of the table relationships.

When users equipped with more capable software encounter a SpeakText table they get a poor experience – essentially, a repetition of the contents for each call. Accordingly, the SpeakText option should be used only if absolutely necessary to accomodate a specific need.

The Generate Speak Text button creates Speak Text in each cell of the table. Speak Text may be individually reviewed and edited via Cell Properties). The Clear Speak Text button removes Speak Text from all cells in the table.

Pass or Fail the Table

At the bottom of the Table Editor window are buttons for Passed, Failed, Skip and End Verification. Their functions are as follows:

Passed: Remediator indicates acceptance of the current state of the table.

Failed: Remediator indicates that the table is not yet accessible as tagged.

Skip: The table is not passed or failed, but remains an open checkpoint for the document.

End Verification: Skips the current table and ends the verification process.